Campbell CR9000, Instruction Manual

Page: 112 / 218

Section 6. Data Table Declarations and Output Processing Instructions
6-24
that were associated with that bin (i.e., number of cycles in bin divided by total
number of cycles counted).
The user enters the number of mean bins, the number of amplitude bins, and
the upper and lower limits of the input data.
The values for the amplitude bins are determined by difference between the
upper and lower limits on the input data and by the number of bins. For
example, if the lower limit is 100 and the upper limit is 150, and there are 5
amplitude bins, the maximum amplitude is 150 - 100 = 50. The amplitude
change between bins and the upper limit of the smallest amplitude bin is 50/5 =
10. Cycles with an amplitude, A, less than 10 will be counted in the first bin.
The second bin is for 10
≤
A < 20, the third for 20
≤
A < 30, etc.
In determining the ranges for mean bins, the actual values of the limits are used
as well as the difference between them. The lower limit of the input data is
also the lower limit of the first mean bin. Assume again that the lower limit is
100, the upper limit 150, and that there are 5 mean bins. In this case the first
bin is for cycles which have a mean value M, 100
≤
M < 110, the second bin
110
≤
M < 120, etc.
If C
m,a
is the count for mean range m and amplitude range a, and M and N are
the number of mean and amplitude bins respectively, then the output of one
repetition is arranged sequentially as (C
1,1
, C
1,2
, ... C
1,N
, C
2,1
, C
2,2
, ... C
M,N
).
Multiple repetitions are sequential in memory. Shown in two dimensions, the
output is:
C
1,1
C
1,2
. . . C
1,N
C
2,1
C
2,2
. . . C
2,N
. . . .
. . . .
. . . .
C
M,1
C
M,2
. . . C
M,N
The histogram can have either open or closed form. In the open form, a cycle
that has an amplitude larger than the maximum bin is counted in the maximum
bin; a cycle that has a mean value less than the lower limit or greater than the
upper limit is counted in the minimum or maximum mean bin. In the closed
form, a cycle that is beyond the amplitude or mean limits is not counted.
The minimum distance between peak and valley, MinAmp, determines the
smallest amplitude cycle that will be counted. The distance should be less than
the amplitude bin width ([high limit - low limit]/no. amplitude bins) or cycles
with the amplitude of the first bin will not be counted. However, if the value is
too small, processing time will be consumed counting "cycles" which are in
reality just noise.
Outputs Generated: No. Mean Bins x No. Amplitude Bins x Reps